Fluid displacing pump



y 1935- E. F. M C RTHY 2,003,117

FLUID DISPLACING PUMP Filed May 26, 1934 v Inventor Edwardlrflfa a rtfy y W 0- my Patented May 28, 1935 UNITED STATESPATENT OFFICE FLUID DISPLACING rum Edward F. McCarthy, Chicago, Ill., assignor of one-half to Charles H. McCarty, Chicago, 111.

Application May 26, 1934, Serial No. 727,601

' 3 Claims. '(Cl. 230-) This invention relates to improvements in fluid displacing pump and more particularly, but not exclusively, high vacuum pumps especially useful in maintaining high vacuums in condenser systems and the like.

One general object of the invention is to provide a pump of the character indicated which is extremely eflicient in operation; cfiects an exceptionally high vacuum; and is of simple and relatively inexpensive construction.

More specifically, an object of the invention is to provide a centrifugally operating pump of the character indicated wherein the impeller operates within the body ofa circulating liquid and the vanes thereof are passed successively over liquid and fluid outlet ports of a stationaryvalve or post member, the construction being further characterized by the employment of stationary baflles and strippers around the impeller 50 located and arranged as to insure maintenance of the displacement or vacuum areas on the inner sides of the impeller vanes and to separate the gaseous fluids near the peripheralportions of the impeller from the slugs of liquid carried thereby when passing from aposition over the liquid outlet port to the fluid outlet port.

Other objects of the invention will more clear-g ly appear from the description and claims hereinafter following.

In the drawing forming a part of this specification, Figure 1 is a vertical diametrical sectional view of a pump having incorporated therein one embodiment of the invention. Figures 2, 3 and 4 are vertical, sectional views corresponding to the section lines 2--2, 3-3 and 4-4 respectively of Figure 1, Figures '2 and 4 being upon an enlarged scale. And Figure 5 is a detailed sectional View corresponding to the section line 55 of Figure 2.

In said drawing, acas'ing or vessel-of suitable form and capacity is provided, the same preferably being comprlsed of a main casting having an outer vertical end wall l 0, bottom wall H, LI-shaped side walls l2|2, intermediate partition I 3 and opposite end wall 14 having anopening therein for the reception of a liquid-tight removable closure wall IS. The capacity of the casing is preferably augmented by means of a box-like superstructure l6 removably secured thereto but with a sealed joint, said box-like member it having a sloping partition I! therein and provided with a fluid outlet pipe I 8 and liquid overflow pipe 19. From the precedingdescription, it will be seen that the casing provides two chambers 20 and2l for the circulating ,liquid which circulates in the direction indicated by the arrows shown in Figure 1 Preferably formed integral with the end wall In is an annular hollow ring-like fluid admission chamber 82 to'which the fluid to be displaced, such as air, is admitted as by the inlet pipe 8|. On the opposite or inner side of'the end wall I0 is preferably integrally formed upper and lower approximately semi-circular fluid Passages 22-922, the interiors 23 of which are incom-v munication with the fluid chamber 20. As will be obvious,- the stationary passages 22 are disposed within the liquid chamber 20 and the circulating liquid is admitted between the members 22 throughthe diametrically disposed ports24, 15,;- as indicated by the arrows in Figure 3.

The dividing partition l3 of the casing is centrally apertured-and is adapted to have removably attached thereto what maybe termed a ported stationary postor valve member desig- 2o ated generally by the reference character A, it being understood that a sealed joint is effected between the member A and the partition 13 when the same are boltedtogether as by the bolts 25 extended through the peripheral flange oi. the member A. Said member A comprises two central, approximately semi-circular sectioned hollow posts 26--26, each ofthe same having an inner flat, transversely extending section 21,

an outer circular section 28 and end wall 89, 30

The two sections 26, as best shown in Figure 2, are separated and provide a diametrical passage 29 with end outlet ports 30-3E!, the inlet for the passage 29 being axially alined with the liquid passage provided between the two fluid con- 35 ducting sections 2323 shown in Figure 3. The V circular outer'section 28 of each post member is provided with a fluid outlet port 31, the same being disposed at with reference to the liquid outlet ports 30 in the embodiment shown in 49 the drawing. As will be apparent, the fluid, such as air, is admitted to the post sections .26 through the righthand ends of the latter, as viewed Figure 1 and which are in alinement with the fluid passages 23 previously referredto.

In addition to the post or valve sections 25, the member A has preferablyiormed integrally therewith arcuate and concentric partitions or baflles 32 -32 and strippers or diffusers 33 33. The baffles 32 as shown in Figure 2, are dis- 50 posed opposite the fluid outlet ports 3| and are of considerable extent circumferentiallyso as to extend considerably to each side of thecor responding port 3!, but not over the liquid outlet ports 39. Thestrippers 33, preferably of spiral 5? or involute form, are so disposed that the advance or separating edges 34 thereof are opposite the liquid outlet ports 3%. As best shown in Figure 5, the strippers have associated therewith at each end thereof not only the attaching flange 35 of the member A but also opposite flanges 38 so as to provide defined passages for the discharge of the slugs of liquid under centrifugal force through the discharge openings 31--3'I.

Cooperable with the stationary post or valve member A is the impeller the reference character B, the latter having a hub 38 keyed to the operating shaft 39, a main web 40 and a pair of integral annular webs 4| and 42 encircling the post members 26-26. Ex-

tending between and integrally formed with the,

impeller web sections 4! and'42 is a series of involute vanes 43-43, the inner edges of which are adapted to rotate over andin close proximity to the post members 26-26 and the outer edges of which pass in close proximity to the stationary baffles 32 and advance separating edges of the strippers 33, as will be apparent from Figure 2.

The shaft 39 is mounted in suitable outboard bearings 44-44 onopposite sides of the casing and suitable packing and glands, as indicated at 45-45, are provided where the shaft extends through the end wall In and removable closure wall [5. j I

Assuming a proper quantity of liquid within the casing and the shaft rotated under relatively high speed as by a suitable motor or other prime mover, the operation of the pump is as follows. As the vanes of the impeller successively pass over the liquid outlet ports 30 of the post member, slugs of the liquid arerobviously picked up thereby and moved out under centrifugal force, as will be apparent. There is thus created on the under or inner sides of the vanes, an area of decreased or lowered'pressure creating a vacuum so that, as the vanes thereafter successively pass over the fluid outlet ports 3|, the air or other fluid passes out through said ports into the area of reduced pressure beneath thevanes. Asthe vanes pass under the strippers 33, por tions of the slugs of liquid will be thrown out or discharged through the discharge ports 31 while the remaining portions .of the liquid slugs as the vanes-pass beneath the stationary baffles 32, will be retained between the baffles and the outer end portions of the vanes, thus providing a seal as the vanes pass beneath the baffles 32 and over the fluiddischarge ports 3|. In this manner, by thus maintaining the seal, maintenance of the areas of reduced pressure beneath the impellers is insured as the vanes pass over the fluid outlet ports 3|.

By employing the strippers or separators 33, the fluid as delivered from one fluid outlet port to the under sides of the vanes, is prevented from being'carried around to a position opposite the next fluid outlet port since the fluid being lighter than the liquid, tends to seek the periphery of the impeller as the vanes of. the latter pass out from under the stationary baflles 32 and hence, in the movement from the rear edge of a baffle 32 to the next adjacent stripper the fluid, such as air, will be separated or stripped by the stripper from they corresponding slug of liquid then being picked up bythe vane as it passes over the cor- 'respondingadjacent liquid outlet port 33 of the post member. This further insures the maintenance of the vacuum or area of reduced pres.- J

designated generally by 'bers to said valve member and thence to sure beneath the vanes as the latter pass beneath the stationary baffles 32.

Obviously, as the liquid and fluid are discharged into the chamber 2|, both rise therein and the gaseous fluid then separates from the liquid and passes out through the outlet pipe i3 and the liquid then circulates over the inclined partition I! and back through the casing through the chamber 20 as before. The partition or bafiie I1 is preferably disposed in the manner shown in Figure 1 so as to provide a larger area on the lefthand side thereof for easier freeing of the air or fluid from the liquid.

Although the preferred form of the invention has herein been shown and described, nevertheless the same is by way of. illustration only and not by way of limitation since it is obvious that various changes and modifications may be made as, for instance, in the number and character of the vanes on the impeller, the number of ports in the post or port member as well as variations in the location and extent of the bafiies and strippers 32 and 33. All changes and modifications are contemplated that come within the scope of the claims appended hereto,

What is claimed is:

1. In' a pump of the character described, the combination with a casing to contain a circulating liquid and provided with a fluid outlet; of a stationary member within the casing andported for the inlet and outlet of a liquid respectively from and return to the casing, said member being also independently ported for the inlet of a fluid from the exterior of the casing and for the outlet of the fluid into the casing; a vaned impeller rotatable about said stationary member in such manner that the inner ends of the vanes successively pass over the liquid and fluid outlet ports of said member; a stationary partition exteriorly concentric with the impeller and disposed opposite the fluidport outlet of. the stationary member to thereby maintain an area of reduced pressure beneath a vane while passing over the fluid outlet; a stationary fluid stripper adjacent the periphery of the impeller and having its advance edge opposite the liquid outlet port of the stationary member, said partition and stripper being spaced from each other to thereby permit the discharge of liquid and fluid from the impeller into the casing; and means for conducting the fluid to be displaced from outside of the casing to said stationary member.

2. In a pump of the character described, the combination with a chambered casing adapted to contain a circulating liquid and provided with a fluid outlet; of a stationary valve member disposed within one of the chambers and having circumferentially spaced independent liquid and fluid outlet ports; means for admitting the circulating liquid from the other of said chamsaid liquid outlet port; means for admitting fluid from a source exterior of the casing to said valve member and to said fluid valve outlet port; an impeller having involute vanes rotatable around said valve member and successively pas said liquid and fluid outlet ports; and stationary, circumferentially spaced and alternated baflie and stripping means around the periphery of, the impeller, the spaces between said baflle and strippingmeans communicating with that chamber in which the stationary valve member is disposed whereby the liquid and fluid are discharged into said chamber from the impeller.

3. In a pump of the character described, the

combination with a casing having a partition therein dividing the same into two chambers for the circulation of a liquid therethrough and provided with a fluid discharge outlet; of a stationary valve member disposed within one of said chambers, said valve member having alternated circumferentially separated and independent liquid and fluid outlet ports, said valve member having an inlet for the circulating liquid from the other of said chambers and an independent fluid inlet from the exterior of the casing; stationary circumferentially spaced and alternated strippers and bafiles arranged around said valve member, the strippers extending over the liquid outlet ports and the bafiles over the fluid outlet ports the spaces between the strippers and baffles communicating with that chamber in which the stationary valve member is disposed whereby the liquid and fluid are discharged into said chamher from the impeller; 'and a vaned impeller cooperable with and rotatable between the valve member and said strippers and baflies.

EDWARD F. MCCARTHY. 

